What action takes place when a frame entering a switch has a unicast destination MAC address appearing in the MAC address table?
- The switch resets the refresh timer on all MAC address table entries.
- The switch forwards the frame out of the specified port.
- The switch updates the refresh timer for the entry.
- The switch will forward the frame out all ports except the incoming port.
| Explanation & Hint:
When a frame entering a switch has a unicast destination MAC address that already appears in the MAC address table, the switch will update the refresh timer for the entry associated with that MAC address. This is because the MAC address table, also known as the CAM (Content Addressable Memory) table, maintains a time stamp for each dynamic entry. Additionally, the switch forwards the frame out of the specific port associated with the destination MAC address. This action is part of the normal switch operation to direct frames only to the port where the destination device is located, thereby conserving bandwidth on other ports. It’s important to note that the switch does not reset the timer for all MAC address table entries, only for the entry corresponding to the destination MAC address of the frame. |